Consumer medicine information

Betaloc Injection

Metoprolol tartrate

BRAND INFORMATION

Brand name

Betaloc

Active ingredient

Metoprolol tartrate

Schedule

S4

 

Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Betaloc Injection.

What is in this leaflet

This leaflet answers some of the common questions people ask about BETALOC INJECTION. It does not contain all the information that is known about BETALOC INJECTION.

It does not take the place of talking to your doctor or pharmacist.

All medicines have risks and benefits. Your doctor will have weighed the risks of your being given BETALOC INJECTION against the benefits they expect it will have for you.

This medicine is likely to be used in emergency situations where you may be unconscious. If possible, please read this leaflet carefully before this medicine is given to you. In some cases this leaflet may be given after the medicine has been used.

If you have any concerns about being given this medicine, ask your doctor or pharmacist.

Keep this leaflet. You may need to read it again.

What BETALOC INJECTION is for

BETALOC INJECTION belongs to a group of medicines called beta-blockers.

BETALOC INJECTION is used to treat irregular heartbeat, also known as arrhythmia, which means that there is a disturbance of the heart's normal rhythm or beat.

Arrhythmias may be caused by a number of factors, including some heart diseases, an overactive thyroid gland, or chemical imbalances. Also, after a heart attack there is a chance of developing arrhythmias.

BETALOC INJECTION helps to restore your heart beat to a more normal rate, particularly if it is beating very fast.

Your doctor will have explained why you are being treated with BETALOC INJECTION and told you what dose you will be given.

Ask your doctor if you have any questions about why BETALOC INJECTION has been prescribed for you. Your doctor may have prescribed this medicine for another reason.

Follow all directions given to you by your doctor carefully. They may differ from the information contained in this leaflet.

BETALOC INJECTION is not addictive.

Before you are given BETALOC INJECTION

When you must not be given it

Do not use BETALOC INJECTION if:

  • you have any allergies to metoprolol tartrate, the active ingredient in BETALOC INJECTION, or any of the ingredients listed at the end of this leaflet, or any other beta-blocker medicine
    Some of the symptoms of an allergic reaction may include shortness of breath, wheezing or difficulty breathing; swelling of the face, lips, tongue or other parts of the body; rash, itching or hives on the skin or you may feel faint.
  • you have asthma, wheezing, difficulty breathing or other lung problems, or have had them in the past
  • you have a history of allergic problems, including hayfever
  • you have low blood pressure
  • you have a very slow heartbeat (less than 45-50 beats/minute)
  • you have certain other heart conditions
  • you have phaeochromocytoma (a rare tumour of the adrenal gland) which is not being treated already with other medicines
  • you have a severe blood vessel disorder causing poor circulation in the arms and legs
  • you are receiving/having emergency treatment for shock or severely low blood pressure.

If you are not sure whether any of these apply to you, check with your doctor.

BETALOC INJECTION should not be used if the expiry date (EXP) printed on the pack has passed or if the packaging is torn or shows signs of tampering. If it has expired or is damaged, return it to your pharmacist for disposal.

Do not give BETALOC INJECTION to children. The safety and effectiveness of BETALOC INJECTION in children has not been established.

If you are not sure whether you should use this medicine, talk to your doctor.

Before you are given it

Tell your doctor if you have any allergies to:

  • metoprolol tartrate or any of the ingredients listed at the end of this leaflet
  • any other medicine or other beta-blocker medicines
  • any other substances, such as foods, preservatives or dyes.

Tell your doctor if you have, or have had, any medical conditions, especially the following:

  • asthma, wheezing, difficulty breathing or other lung problems
  • diabetes
  • an overactive thyroid gland
  • liver problems
  • kidney problems
  • certain types of angina
  • any other heart problems
  • phaeochromocytoma, a rare tumour of the adrenal gland
  • any blood vessel disorders causing poor circulation in the arms and legs.

Tell your doctor if you are pregnant or intend to become pregnant. Like most beta-blocker medicines BETALOC INJECTION is not recommended for use during pregnancy.

Tell your doctor if you are breast-feeding or plan to breast-feed. The active ingredient in BETALOC INJECTION passes into breast milk and therefore there is a possibility that the breast-fed baby may be affected.

If you have not told your doctor about any of the above, tell them before you are given BETALOC INJECTION.

Taking other medicines

Tell your doctor or pharmacist if you are taking any other medicines, including any that you get without a prescription from your pharmacy, supermarket or health food shop.

Some medicines and BETALOC INJECTION may interfere with each other. These include:

  • other beta-blocker medicines, including beta-blocker eye drops
  • calcium channel blockers or calcium antagonists, medicines used to treat high blood pressure and angina, for example verapamil and diltiazem
  • medicines used to treat high blood pressure, for example clonidine, hydralazine, and prazosin
  • medicines used to treat abnormal or irregular heartbeat, for example amiodarone disopyramide and quinidine
  • medicines used to treat arthritis, pain, or inflammation, for example indomethacin and ibuprofen
  • warfarin, a medicine used to prevent blood clots
  • digoxin, a medicine used to treat heart failure
  • medicines used to treat diabetes
  • cimetidine, a medicine used to treat stomach ulcers
  • medicines used to treat bacterial infections, for example rifampicin
  • medicines used to treat depression
  • monoamine-oxidase inhibitors (MAOIs).

These medicines may be affected by BETALOC INJECTION or may affect how well it works.

You may need to be given different amounts of your medicine, or you may need to be given different medicines. Your doctor will advise you.

Your doctor and pharmacist have more information on medicines to be careful with or avoid while using BETALOC INJECTION.

If you have not told your doctor about any of these things, tell them before you are given BETALOC INJECTION.

How BETALOC INJECTION is given

BETALOC INJECTION is given as a slow injection into a vein.

BETALOC INJECTION must only be given by a doctor or nurse.

Your doctor will decide what dose and for how long you will receive BETALOC INJECTION. This depends on your condition and other factors, such as your weight.

To begin treatment, up to 5mg of BETALOC INJECTION is given at a rate of 1 to 2mg per minute. This dose may be repeated at 5-minute intervals until a satisfactory effect is achieved.

Your blood pressure and heart will be monitored during the treatment.

If you are given too much

The doctor giving you BETALOC INJECTION will be experienced in its use, so it is unlikely that you will be given an overdose. However, if you are accidentally given an overdose of BETALOC INJECTION you may have nausea, vomiting, convulsions, extreme slowing of the heart beat, lowered blood pressure, possible heart failure and breathing difficulties. In extreme cases, your skin may turn blue, and you may get shock, unconsciousness or coma.

Your doctor has information on how to recognise and treat an overdose. Ask your doctor if you have any concerns.

Side effects

Tell your doctor as soon as possible if you do not feel well while you are being given BETALOC INJECTION.

If you are over 65 years of age you may have an increased chance of getting side effects.

All medicines can have side effects. Sometimes they are serious, most of the time they are not. You may need medical treatment if you get some of the side effects.

Ask your doctor to answer any questions you may have.

Tell your doctor or nurse if you notice any of the following and they worry you:

  • swelling, burning sensation, changes in skin colour or texture where you had the injection
  • swelling or pain in a vein
  • headache, tiredness, drowsiness
  • aches and pains, painful joints
  • nausea (feeling sick), vomiting
  • weakness, lack of energy
  • stomach upset, diarrhoea or constipation
  • dry mouth, changes in taste sensation
  • difficulty sleeping, nightmares
  • mood changes
  • confusion, short-term memory loss, inability to concentrate
  • increased sweating, runny or blocked nose
  • hair loss
  • weight gain.

These side effects are usually mild.

Tell your doctor or nurse if you notice any of the following:

  • dizziness, lightheadedness or fainting especially on standing up, which may be due to low blood pressure
  • tingling or "pins and needles"
  • coldness, burning, numbness or pain in the arms and/or legs
  • skin rash or worsening of psoriasis
  • symptoms of sunburn happening more quickly than before
  • abnormal thinking or hallucinations
  • buzzing or ringing in the ears, deafness
  • irritated eyes or blurred vision
  • sexual problems
  • unusual bleeding or bruising
  • constant "flu-like" symptoms with tiredness or lack of energy.

These are serious side effects. You may need urgent medical attention. Serious side effects are rare.

If any of the following happen, tell your doctor or nurse immediately:

  • shortness of breath, being less able to exercise
  • swelling of the ankles, feet or legs
  • chest tightness, wheezing, noisy breathing, difficulty breathing
  • chest pain, changes in heart rate or palpitations
  • swelling of the face, lips, tongue or throat which may cause difficulty swallowing or breathing
  • yellowing of the skin or eyes (jaundice), generally feeling unwell.

These are very serious side effects. You may need urgent medical attention or hospitalisation. These side effects are rare.

Other side effects not listed here may occur in some patients. Tell your doctor, nurse or pharmacist if you notice anything that is making you feel unwell.

Do not be alarmed by this list of possible side effects. You may not experience any of them.

After using BETALOC INJECTION

Storage

BETALOC INJECTION will be stored in the pharmacy or on the ward.

The injection is kept in a cool dry place, protected from light, where the temperature stays below 25°C.

Product description

What BETALOC INJECTION looks like

BETALOC INJECTION (1mg/mL) is a clear, colourless liquid in glass ampoules of 5mL, in packs of 5.

Ingredients

BETALOC INJECTION does not contain lactose, sucrose, gluten, tartrazine or any other azo dyes.

Each BETALOC INJECTION contains metoprolol tartrate as the active ingredient;
plus

  • sodium chloride
  • water for injections.

Sponsor

AstraZeneca Pty Ltd
ABN 54 009 682 311
66 Talavera Road
MACQUARIE PARK NSW 2113

Telephone: 1800 805 342

Australian Registration Number
Betaloc Injection 5mg/5mL - Aust R 12063

This leaflet was prepared in November 2017.

BETALOC® is a trade mark of the AstraZeneca group of companies.

© AstraZeneca 2017

Published by MIMS January 2018

BRAND INFORMATION

Brand name

Betaloc

Active ingredient

Metoprolol tartrate

Schedule

S4

 

1 Name of Medicine

Metoprolol tartrate.

2 Qualitative and Quantitative Composition

Betaloc tablets contain 50 mg or 100 mg metoprolol tartrate and the following inactive ingredients: lactose monohydrate, cellulose microcrystalline, colloidal anhydrous silica, sodium starch glycollate, povidone and magnesium stearate.
Betaloc Injection solution contains 1 mg/mL metoprolol tartrate and the following inactive ingredients: sodium chloride and water for injections.

3 Pharmaceutical Form

Tablets 50 mg.

White to off-white, circular, biconvex tablet with a diameter of 8 mm, scored and marked A/BB on one side. The score line is only to facilitate breaking for ease of swallowing and not to divide into equal doses.

Tablets 100 mg.

White to off-white, circular, biconvex tablet with a diameter of 10 mm, scored and marked A/ME on one side. The tablet can be divided into equal halves.

Injection solution, 1 mg/mL.

Clear, colourless liquid.

4 Clinical Particulars

4.1 Therapeutic Indications

Oral therapy.

Hypertension, angina pectoris prophylaxis, suspected or definite myocardial infarction, migraine prophylaxis.

Intravenous therapy.

Disturbances of cardiac rhythm, in particular supraventricular tachyarrhythmias.

4.2 Dose and Method of Administration

Oral therapy.

Betaloc (metoprolol tartrate) is recommended for oral therapy in hypertension, angina pectoris, suspected or definite myocardial infarction and migraine prophylaxis.
Betaloc 50 mg tablets are scored to facilitate breaking for ease of swallowing only and not to divide the tablet into equal doses. Betaloc 100 mg tablets can be divided into two equal doses.
Hypertension.

Initially.

Mild hypertensives: 50 or 100 mg once daily, for one week.
Severe hypertensives: 50 or 100 mg twice daily, for one week.

Maintenance.

50 or 100 mg once or twice daily.
Some patients will respond to 50 mg once daily. However, a large number of patients will respond to 100 mg once daily as initial and maintenance therapy. Response is rarely improved by increasing the dose beyond 200 mg daily. The maximum daily dose should not exceed 400 mg. Although twice daily dosage is optimal, in patients where maintenance dose is 150 mg daily or less, it may be administered as a single dose.
Angina pectoris. 50-100 mg two or three times daily.
Myocardial infarction.

Initially.

Therapy should commence with Betaloc (metoprolol tartrate) tablets 50 mg twice daily and be continued for 48 hours.

Maintenance.

The oral maintenance dose is generally 100 mg twice daily.
Migraine prophylaxis. 100-150 mg given in divided doses, morning and evening.

Intravenous therapy.

Betaloc (metoprolol tartrate) injection is suitable for the treatment of disturbances of cardiac rhythm, particularly supraventricular tachyarrhythmias (see Section 5 Pharmacological Properties).
Initially, up to 5 mg is given at a rate of 1 to 2 mg per minute. This dose may be repeated at 5 minute intervals until a satisfactory effect is achieved. A total dose of 10 to 15 mg will generally produce a satisfactory effect. Doses of 20 mg or more are unlikely to result in further therapeutic benefit. Blood pressure and ECG should be monitored during the treatment.
Parenteral administration should be conducted by experienced staff with suitable monitoring and resuscitating equipment available.
Contains no antimicrobial agent. Product is for single use in one patient only. Discard any residue.

Paediatric use.

The safety and efficacy in children have not been established.

4.3 Contraindications

Bronchospasm. Beta-adrenergic blockade of the smooth muscle of bronchi and bronchioles may result in an increased airways resistance. These drugs also reduce the effectiveness of asthma treatment. This may be dangerous in susceptible patients.
Therefore, beta-blockers are contraindicated in any patient with a history of airways obstruction or a tendency to bronchospasm. Use of cardioselective beta-blockers can also result in severe bronchospasm. If such therapy must be used, great caution should be exercised. Alternative therapy should be considered.
Allergic disorders (including allergic rhinitis) which may suggest a predisposition to bronchospasm.
Right ventricular failure secondary to pulmonary hypertension.
Significant right ventricular hypertrophy.
Sinus bradycardia (less than 45-50 beats/minute).
Second and third degree A-V block.
Shock (including cardiogenic and hypovolaemic shock).
Hypersensitivity to metoprolol tartrate, related derivatives, or any of the excipients in Betaloc. Cross sensitivity between beta-blockers can occur.
Noncompensated congestive heart failure (see Section 4.4 Special Warnings and Precautions for Use).
Sick sinus syndrome (unless a permanent, appropriately functioning pacemaker is in place).
Severe peripheral arterial circulatory disorders.
Myocardial infarction patients with a heart rate of < 45 beats/minute, a PR interval of > 0.24 seconds, a systolic blood pressure of < 100 mmHg, and/or moderate to severe noncompensated heart failure.
Hypotension.
Untreated phaeochromocytoma (see Section 4.4 Special Warnings and Precautions for Use).
Continuous or intermittent inotropic therapy acting through β-receptor agonism.

4.4 Special Warnings and Precautions for Use

Cardiac failure.

Beta-blockade depresses myocardial contractility and may precipitate cardiac failure in some patients with a history of cardiac failure, chronic myocardial insufficiency, or unsuspected cardiomyopathy. In patients without a history of cardiac failure, continuing depression of the myocardium may lead to cardiac failure. If signs of cardiac failure are present, the patient should be fully digitalised and/or given a diuretic and carefully monitored. If cardiac failure persists, Betaloc (metoprolol tartrate) should be discontinued gradually (see Section 4.4 Special Warnings and Precautions for Use, Abrupt withdrawal).
Beta-blockers should not be used in patients with untreated congestive heart failure. This condition should first be stabilised.

Note.

Although congestive heart failure has been considered to be a contraindication to the use of beta-blockers, there is growing literature on the experimental use of beta-adrenergic blocking drugs in heart failure. As further trials are needed to identify which patients are most likely to respond to which drugs, beta-blockers should not normally be prescribed for heart failure outside specialist centres.

Prinzmetal angina.

There is a risk of exacerbating coronary artery spasm if patients with Prinzmetal or variant angina are treated with a beta-blocker. If this treatment is essential, it should only be undertaken in a coronary or intensive care unit.

Conduction disorders.

Very rarely a pre-existing A-V conduction disorder of moderate degree may become aggravated (possibly leading to A-V block). Betaloc should be administered with caution to patients with first degree A-V block (see Section 4.3 Contraindications).

Phaeochromocytoma.

In patients with this condition, an alpha-blocking drug (e.g. phentolamine/ phenoxybenzamine) should be administered before the beta-blocker to avoid exacerbation of hypertension.

Diabetes.

Betaloc should be used with caution in patients with diabetes mellitus, especially those who are receiving insulin or oral hypoglycaemic agents. Diabetic patients should be warned that beta-blockers affect glucose metabolism and may mask some important premonitory signs of acute hypoglycaemia, such as tachycardia.
In patients with insulin or noninsulin dependent diabetes, especially labile diabetes, or with a history of spontaneous hypoglycaemia, beta-blockade may result in the loss of diabetic control and delayed recovery from hypoglycaemia.
The dose of insulin or oral hypoglycaemic agent may need to be adjusted. Diabetic patients receiving Betaloc should be monitored to ensure diabetes control is maintained.

Allergic conditions.

Allergic reactions may be exaggerated by beta-blockade (e.g. allergic rhinitis during the pollen season and allergic reactions to bee and wasp stings). Beta-blockers should be avoided if there is a risk of bronchospasm.
In patients taking beta-blockers, anaphylactic shock assumes a more severe form and may be resistant to normal doses of adrenaline. Whenever possible, beta-blockers should be avoided in patients who are at increased risk of anaphylaxis.

Hyperthyroidism.

Special care should be exercised in those patients who are hyperthyroid and also receiving beta-blockers because beta-blockers may mask the clinical signs of developing or continuing hyperthyroidism, resulting in symptomatic improvement without any change in thyroid status. Where Betaloc is administered to patients having, or suspected of developing thyrotoxicosis, both thyroid and cardiac function should be closely monitored.

Peripheral vascular disease.

Beta-blockade may impair the peripheral circulation and exacerbate the symptoms of peripheral vascular disease (see Section 4.3 Contraindications).

Use in renal impairment.

In patients with severe renal disease, haemodynamic changes following beta-blockade may impair renal function further. Beta-blockers which are excreted mainly by the kidney may require dose adjustment in patients with renal failure.

Use in hepatic impairment.

Metoprolol is mainly eliminated by hepatic metabolism (see Section 5.2 Pharmacokinetic Properties). Therefore, liver cirrhosis may increase the systemic bioavailability of metoprolol and reduce its total clearance, leading to increased plasma levels.

Intravenous therapy.

The intravenous administration of metoprolol tartrate to patients with a systolic blood pressure below 100 mmHg (13.3 kPa) should be carried out with special care as it can result in a further significant decrease of blood pressure.

Concomitant therapy with calcium antagonists.

The concomitant use of calcium antagonists with myocardial suppressant and sinus node activity (e.g. verapamil and to a lesser extent diltiazem) and beta-blockers may cause bradycardia, hypotension and asystole. Extreme caution is required if these drugs have to be used together.
A calcium antagonist of the phenylalkylamine type (e.g. verapamil) should not be administered intravenously to patients receiving metoprolol because there is a risk of cardiac arrest in this situation. Patients taking oral calcium antagonists of this type in combination with metoprolol should be closely monitored.
The combination of beta-blockers with dihydropyridine calcium channel blockers with a weak myocardial depressant effect (e.g. felodipine, nifedipine) can be administered together with caution. In case excess hypotension develops, the calcium antagonist should be stopped or the dosage reduced.

Clonidine.

Concurrent use of beta-blockers and clonidine should be avoided because of the risk of adverse interaction and severe withdrawal symptoms. If administered concomitantly, the clonidine should not be discontinued until several days after the withdrawal of the beta-blocker.

Antiarrhythmic drugs.

Care should be taken when prescribing beta-blockers with antiarrhythmic drugs. Interactions have been reported during concomitant beta-blocker therapy with the class IA agents disopyramide, and less frequently quinidine; class IB agents, tocainide, mexiletine and lignocaine; class IC agents, flecainide and propafenone (not available in Australia); the class III agent, amiodarone; and the class IV antiarrhythmic agents (e.g. verapamil).

Catecholamine depleting agents.

Concomitant use of drugs such as reserpine and guanethidine requires careful monitoring since the added effect of a beta-blocker may produce an excessive reduction of the resting sympathetic nervous tone.

General anaesthesia.

Beta-blockade may have beneficial effects in decreasing the incidence of arrhythmias and myocardial ischaemia during anaesthesia and the postoperative period. It is currently recommended that maintenance beta-blockade be continued perioperatively. The anaesthetist must be made aware of beta-blockade because of the potential for interactions with other drugs, resulting in severe bradyarrhythmias and hypotension, the decreased reflex ability to compensate for blood loss, hypovolaemia and regional sympathetic blockade, and the increased propensity for vagal induced bradycardia. Incidents of protracted severe hypotension or difficulty restoring normal cardiac rhythm during anaesthesia have been reported.
Acute initiation of high dose metoprolol to patients undergoing noncardiac surgery should be avoided, since it has been associated with bradycardia, hypotension and stroke including fatal outcome in patients with cardiovascular risk factors.
Modern inhalational anaesthetic agents are generally well tolerated, although older agents (ether, cyclopropane, methoxyflurane, trichlorethylene) were sometimes associated with severe circulatory depression in the presence of beta-blockade. If it is thought necessary to withdraw beta-blocker therapy before surgery, this should be done gradually and completed about 48 hours before surgery (see Section 4.4 Special Warnings and Precautions for Use, Abrupt withdrawal).

Effects on the heart rate.

If the patient develops increasing bradycardia (heart rate less than 50 to 55 beats/minute) the dosage of Betaloc should be gradually reduced or treatment gradually withdrawn (see Section 4.3 Contraindications).

Effects on the thyroid.

The effects of beta-blockers on thyroid hormone metabolism may result in elevations of serum free thyroxine (T4) levels. In the absence of any signs or symptoms of hyperthyroidism, additional investigation is necessary before a diagnosis of thyrotoxicosis can be made.

Other metabolic effects.

Beta-adrenoreceptors are involved in the regulation of lipid as well as carbohydrate metabolism. Some drugs affect the lipid profile adversely although the long-term clinical significance of this change is unknown and the effect appears to be less for drugs with intrinsic sympathomimetic activity.

Effects on the eye and skin.

Various skin rashes and conjunctival xerosis have been reported with beta-blocking agents. Cross reactions may occur between beta-blockers, therefore substitutions within the group may not necessarily preclude occurrence of symptoms.
During long-term treatment with the beta-blocking drug practolol a specific rash bearing a superficial resemblance to psoriasis was occasionally described. In a number of the patients affected, this rash was accompanied by adverse effects on the eye (xerophthalmia and/or keratoconjunctivitis) of varying severity. This condition is called the oculomucocutaneous or practolol syndrome. On a few rare occasions, serious otitis media, sclerosing peritonitis and pleurisy have been reported as part of this syndrome.
The oculomucocutaneous syndrome as reported with practolol has not been reported with metoprolol. However, dry eyes and skin rash have been reported with metoprolol. If such symptoms occur, discontinuation of metoprolol should be considered.
More recently, an association between Peyronie's disease (a fibrosing induration of the penis) and various beta-blockers has been suggested but is not proven.

Abrupt withdrawal.

Care should be taken if beta-blockers have to be discontinued abruptly in patients with coronary artery disease. Severe exacerbation of angina and precipitation of myocardial infarction and ventricular arrhythmias have occurred following abrupt discontinuation of beta-blockade in patients with ischaemic heart disease.
Therefore, it is recommended that the dosage be reduced gradually over a period of 8-14 days during which time the patient's progress should be assessed. Betaloc should be temporarily reinstituted if the angina worsens.
If the drug must be withdrawn abruptly in these patients, close observation is required. In the perioperative period Betaloc (metoprolol tartrate) should not be withdrawn unless withdrawal is specifically indicated.

Use in the elderly.

See Section 5.2 Pharmacokinetic Properties, Pharmacokinetics in the elderly.

Paediatric use.

The safety and efficacy in children have not been established.

Effects on laboratory tests.

No data available.

4.5 Interactions with Other Medicines and Other Forms of Interactions

Other antihypertensive agents.

Metoprolol enhances the effects of other antihypertensive drugs. Particular care is required when initiating administration of a beta-blocker and prazosin together.

Sympathetic ganglion blocking agents, other beta-blockers or monoamine oxidase (MAO) inhibitors.

Patients receiving concomitant treatment with sympathetic ganglion blocking agents, other beta-blockers (including eye drops), or monoamine oxidase (MAO) inhibitors should be kept under close surveillance.

Clonidine.

If concomitant treatment with clonidine is to be discontinued, the beta-blocker medication should be withdrawn several days before clonidine. The rebound hypertension associated with clonidine withdrawal can be exacerbated by the presence of a beta-blocker. If both drugs are withdrawn simultaneously, a marked rise in blood pressure and/or arrhythmias may result.

Calcium antagonists.

When metoprolol is given together with calcium antagonists of the verapamil and diltiazem type the patient should be monitored for possible negative inotropic and chronotropic effects. Calcium antagonists of the verapamil type should not be given by intravenous administration to patients treated with beta-blockers.

Antiarrhythmic agents.

When metoprolol is given together with antiarrhythmic agents the patient should be monitored for possible negative inotropic and chronotropic effects. The negative inotropic and negative chronotropic effects of antiarrhythmic agents of the quinidine type and amiodarone may be enhanced by beta-blockers.

Prostaglandin synthetase inhibiting agents.

Concomitant treatment with indomethacin or other prostaglandin synthetase inhibiting agents may decrease the antihypertensive effect of beta-blockers.

Alcohol.

Metoprolol may modify the pharmacokinetic behaviour of alcohol when taken together. The plasma level of metoprolol may be raised by alcohol.

Liver enzyme effects.

Enzyme inducing and enzyme inhibiting substances may change the plasma level of metoprolol. The plasma level of metoprolol is lowered by rifampicin and may be raised by cimetidine, alcohol, hydralazine and selective serotonin reuptake inhibitors (SSRIs), e.g. paroxetine, fluoxetine and sertraline.

Oral antidiabetic agents.

The dosages of oral antidiabetics may need to be adjusted in patients receiving beta-blockers (see Section 4.4 Special Warnings and Precautions for Use).

Anaesthetics.

Inhalation anaesthetics enhance the cardiosuppressant effect of beta-blocker therapy (see Section 4.4 Special Warnings and Precautions for Use). Metoprolol may also reduce the clearance of other drugs (e.g. lignocaine).

Warfarin.

A limited number of reports have demonstrated a rise in AUC and concentration of warfarin when taken with another beta-blocker. This could potentially increase the anticoagulant effect of warfarin.

Digitalis glycosides.

Digitalis glycosides, in association with beta-blockers, may increase atrioventricular conduction time and may induce bradycardia.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

No data available.
(Category C)
Betaloc should not be given during pregnancy unless its use is considered essential. In general, β-blockers reduce placental perfusion, which has been associated with growth retardation, intrauterine death, abortion and early labour. It is therefore suggested that appropriate maternofetal monitoring be performed in pregnant women treated with metoprolol. Beta-blockers may cause bradycardia in the foetus and new-born infant.
Metoprolol crosses the placental barrier in pregnant women; in one study the concentration in the umbilical vein was almost the same as in maternal vein plasma.
During the late stages of pregnancy these drugs should only be given after weighing the needs of the mother against the risk to the foetus.
The lowest possible dose should be used and discontinuation of treatment should be considered at least 2 to 3 days before delivery to avoid increased uterine contractility and effects of beta-blockade in the newborn (e.g. bradycardia, hypoglycaemia).
Metoprolol is excreted in human breast milk. Beta-blockers taken by the mother may cause side effects, e.g. bradycardia, in the breastfed infant, although when the doses used are within the recommended therapeutic range, the very small amount of drug ingested by the infant renders such effects unlikely.
Experience suggests that Betaloc (metoprolol tartrate) only need be discontinued during lactation if the infant's hepatic function is severely impaired.

4.7 Effects on Ability to Drive and Use Machines

Betaloc may cause dizziness, fatigue or visual disturbances (see Section 4.8 Adverse Effects (Undesirable Effects)) and, therefore, may adversely affect the patient's ability to drive or use machinery.

4.8 Adverse Effects (Undesirable Effects)

Occasionally, especially at the start of treatment, beta-blockers may give rise to gastrointestinal upsets, sleep disturbances, or exertional tiredness. These effects, however, are of a mild nature and seldom necessitate a reduction in the dosage.
The following events have been reported as adverse events in clinical trials or reported from routine use. In many cases a relationship with metoprolol has not been established. The following definitions of frequency are used: very common ≥ 10%; common 1-9.9%; uncommon 0.1-0.9%; rare 0.01-0.09%; very rare < 0.01%.

Cardiovascular.

Common: bradycardia, postural disorders (very rarely with syncope), cold hands and feet (Raynaud's phenomenon), palpitations, clinically significant falls in blood pressure after intravenous administration. Uncommon: transient deterioration of heart failure symptoms, A-V block I, oedema, precordial pain, cardiogenic shock in patients with acute myocardial infarction*. Rare: disturbances of cardiac conduction, cardiac arrhythmias. Very rare: gangrene in patients with pre-existing severe peripheral circulatory disorders.
*Excess frequency of 0.4% compared with placebo in a study of 46,000 patients with acute myocardial infarction where the frequency of cardiogenic shock was 2.3% in the metoprolol group and 1.9% in the placebo group in the subset of patients with low shock risk index. The shock risk index was based on the absolute risk of shock in each individual patient derived from age, sex, time delay, Killip class, blood pressure, heart rate, ECG abnormality, and prior history of hypertension. The patient group with low shock risk index corresponds to the patients in which metoprolol is recommended for use in acute myocardial infarction.

Central nervous system.

Very common: fatigue. Common: dizziness, headache. Uncommon: paraesthesia, muscle cramps.

Gastrointestinal.

Common: nausea, diarrhoea, constipation, abdominal pain. Uncommon: vomiting. Rare: dry mouth.

Haematologic.

Very rare: thrombocytopenia.

Hepatic.

Rare: liver function test abnormalities. Very rare: hepatitis.

Metabolic.

Uncommon: weight gain.

Psychiatric.

Uncommon: depression, impaired concentration, somnolence or insomnia, nightmares. Rare: nervousness, anxiety, impotence/ sexual dysfunction. Very rare: amnesia/ memory impairment, confusion, hallucinations.

Respiratory.

Common: dyspnoea on exertion. Uncommon: bronchospasm (which may also occur in patients without a history of obstructive lung disease). Rare: rhinitis.

Sense organs.

Rare: disturbances of vision, dry and/or irritated eyes, conjunctivitis (see Section 4.4 Special Warnings and Precautions for Use). Very rare: tinnitus, taste disturbances.

Skin.

Uncommon: rash (in the form of urticaria, psoriasiform and dystrophic skin lesions), increased sweating. Rare: loss of hair. Very rare: photosensitivity reactions, aggravated psoriasis.

Miscellaneous.

Very rare: arthralgia.

Reporting suspected adverse effects.

Reporting suspected adverse reactions after registration of the medicinal product is important. It allows continued monitoring of the benefit-risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions at www.tga.gov.au/reporting-problems.

4.9 Overdose

Symptoms.

Symptoms of overdosage may include severe hypotension, cardiac insufficiency, bradycardia and bradyarrhythmia, cardiac conduction disturbances, cardiogenic shock, cardiac arrest, impairment of consciousness/ coma, convulsions and bronchospasm. The main clinical signs of overdosage are cardiovascular and in some cases decompensation may be rapid. Overdosage with Betaloc can lead to death.
Cases of overdosage in paediatric patients need to be given extra attention even if the patient appears well on presentation and even if only a small number of tablets have apparently been taken.

Management.

For information on management of overdose, contact the Poisons Information Centre on 131126 (Australia).
Care should be provided at a facility that can provide appropriate supporting measures, monitoring, and supervision.
Activated charcoal may reduce absorption of the medicine if given within one or two hours after ingestion. In patients who are not fully conscious or have impaired gag reflex, consideration should be given to administering activated charcoal via a nasogastric tube, once the airway is protected.
Syrup of ipecac and gastric lavage are no longer considered to be standard therapy for gut decontamination.
Atropine, adrenostimulating drugs or pacemaker to treat bradycardia and conduction disorders.
Hypotension, acute cardiac failure, and shock to be treated with suitable volume expansion, injection of glucagon (if necessary, followed by an intravenous infusion of glucagon), intravenous administration of adrenostimulating drugs such as dobutamine, with α1-receptor agonistic drugs added in presence of vasodilation. Intravenous use of calcium salts (Ca2+) can also be considered.
Bronchospasm can usually be reversed by bronchodilators.

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action.

Betaloc (metoprolol tartrate) is a relatively cardioselective beta-adrenoreceptor blocking drug without intrinsic sympathomimetic activity, and is suited for the treatment of hypertension. It acts on β1-receptors mainly located in the heart at lower doses than those needed to influence the β2-receptors mainly located in the bronchi and peripheral vessels. Betaloc (metoprolol tartrate) reduces the blood pressure in patients with hypertension, in both the standing and supine position. It also reduces the extent of rises in blood pressure occurring in response to physical and mental stress.
In angina pectoris metoprolol reduces the frequency and severity of the attacks and the need for glyceryl trinitrate relief, and increases exercise tolerance.
Metoprolol has been shown to reduce mortality in patients with suspected or definite myocardial infarction. The mechanisms of action for these effects of metoprolol are not fully understood but may be related to a lower incidence of ventricular fibrillation and limitation of infarct size. Metoprolol has also been shown to reduce the incidence of recurrent myocardial infarction.
In cases of supraventricular tachycardia or atrial fibrillation, and in the presence of extrasystoles, metoprolol has a regulating effect on the heart rate.
Orthostatic reactions or disturbances of electrolyte balance have not been observed.
In therapeutic doses, Betaloc (metoprolol tartrate) has less effect on the peripheral circulation and the bronchial muscles than nonselective beta-blockers. However, Betaloc (metoprolol tartrate) should be used with caution in patients with asthma, and concomitant use of an adrenergic bronchodilator, e.g. terbutaline or salbutamol, is advisable. Patients with reversible airways obstruction who are already taking beta-2 stimulants may require adjustment of the dosage of these if metoprolol tartrate therapy is subsequently introduced.
The stimulant effect of catecholamines on the heart is reduced or inhibited by metoprolol. This leads to a decrease in heart rate, cardiac contractility, and cardiac output. Betaloc (metoprolol tartrate) will inhibit catecholamine induced lipolysis.
Betaloc (metoprolol tartrate) has also been shown to reduce diuretic induced increase in plasma renin activity. Betaloc (metoprolol tartrate) will inhibit catecholamine induced insulin secretion to a far lesser degree than nonselective beta-blockers.
Betaloc (metoprolol tartrate) is practically devoid of membrane stabilising activity and does not display partial agonist activity (i.e. intrinsic sympathomimetic activity = ISA) at doses required to produce beta-blockade.
Betaloc (metoprolol tartrate) forms an active metabolite (2-hydroxymetoprolol), which does not, however, contribute significantly to the therapeutic effect.
Betaloc (metoprolol tartrate) is considered a relatively lipid soluble compound, i.e. less soluble than propranolol and more lipid soluble than atenolol.
Metoprolol has been shown to exert a prophylactic effect in both classical and common migraine.

Clinical trials.

No data available.

5.2 Pharmacokinetic Properties

Absorption and distribution.

Betaloc (metoprolol tartrate) is rapidly and almost completely (more than 95%) absorbed from the gastrointestinal tract. It is rapidly and extensively distributed to the extravascular tissues. The volume of distribution is 5.6 L/kg. At therapeutic concentrations, approximately 12% of Betaloc (metoprolol tartrate) is bound to human serum proteins.

Metabolism and excretion.

Studies with the radioactively labelled drug have shown that more than 90% of the dose is excreted in the urine within 72 hours, mainly in the form of known metabolites. Only about 3% of the administered dose is excreted unchanged in the urine in 72 hours. The rate of renal excretion of metoprolol tartrate has a linear relationship to its plasma concentration. Betaloc (metoprolol tartrate) is excreted mainly by glomerular filtration.
Long-term studies have shown that Betaloc (metoprolol tartrate) neither enhances nor inhibits its own metabolism.
The elimination half-life of metoprolol tartrate is between 3 and 5 hours.

Dose response.

The duration of the beta-blocking effect is dose dependent (as measured by reduction of exercise heart rate). For instance, in healthy subjects the effect of 20 mg metoprolol tartrate given intravenously is halved after about 6 hours.

Pharmacokinetics in the elderly.

Elderly subjects showed no significant differences in the plasma concentrations of metoprolol as compared with young subjects, in a study involving eight healthy elderly (mean age 74.5 years) and eight healthy young (mean age 26.3 years) subjects.

5.3 Preclinical Safety Data

Genotoxicity.

No data available.

Carcinogenicity.

No data available.

6 Pharmaceutical Particulars

6.1 List of Excipients

See Section 2 Qualitative and Quantitative Composition.

6.2 Incompatibilities

Incompatibilities were either not assessed or not identified as part of the registration of this medicine. See Section 4.5 Interactions with Other Medicines and Other Forms of Interactions for information regarding interactions.

6.3 Shelf Life

In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry date can be found on the packaging.

6.4 Special Precautions for Storage

Betaloc tablets: Store below 30°C. Protect from moisture.
Betaloc injection: Store below 25°C. Protect from light.

6.5 Nature and Contents of Container

Tablets 50 mg.

Available in blister packs of 100 tablets.

Tablets 100 mg.

Available in blister packs of 60 tablets.

Injection solution, 1 mg/mL.

Available in glass ampoules of 5 mL, in packs of 5.

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of by taking to your local pharmacy.

6.7 Physicochemical Properties

Metoprolol tartrate, di(±)-1-(isopropylamine)-3-[p-(2-methoxyethyl)phenoxy]-2 propranol L(+)-tartrate, is a white crystalline powder with a melting point of approximately 120°C. The powder is practically odourless. It is very soluble in water, soluble in chloroform, methylene chloride and alcohol, and almost insoluble in benzene, diethylether and acetone.
Metoprolol tartrate is structurally related to other cardioselective beta-blockers.
The molecular formula is (C15H25NO3)2, C4H6O6.

Chemical structure.


CAS number.

56392-17-7.

7 Medicine Schedule (Poisons Standard)

S4.

Summary Table of Changes